Method and apparatus for cleaning integrated circuit wafers

US5505785A · kind A · utility

Inventor

• Gary W. Ferrell · Rue de l'Église, US

Key dates

• Filing date: Jul 18, 1994
• Grant date: Apr 9, 1996
• Expiry date: Jul 18, 2014

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/67057
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A method and apparatus for removing particle, metallic and organic contamination from the wafers used in fabricating integrated circuits is disclosed. In the preferred embodiment, the method comprises the step of placing the wafers to be processed in a vessel or container constructed of a very pure metal, and upon which a surface oxide will quickly form in air. The metal vessel or container is then filled with a cleaning solvent such as sulfuric acid, and are ultrasonically vibrated to remove the contamination. The ultrasonic vibration causes an acoustic streaming of the sulfuric acid, leading to a microflow of the solvent across the surface of the wafer at speeds on the order of several meters per second. This microflow provides for an quick and efficient cleaning of the wafer at reduced temperatures, thereby increasing the overall throughput of the planar fabrication process. The apparatus comprises a vessel or container constructed from a very pure metal, and containing an acidic cleaning solvent. The metal vessel or container is coupled to an ultrasonic vibrating device which ultrasonically vibrates the vessel or container, thereby cleaning the wafers.